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On the border of two phases of a building life cycle (LC), the programming phase (conception and design) and the execution phase, a contractor is selected. A particularly appropriate method of selecting a contractor for the construction market is the tendering system. It is usually based on quality and price criteria. The latter may involve the price (namely, direct costs connected with works realization as well as mark-ups, mainly overhead costs and profit) or cost (based on the life cycle costing (LCC) method of cost efficiency). A contractor’s decision to participate in a tender and to calculate a tender requires an investment of time and company resources. As this decision is often made in a limited time frame and based on the experience and subjective judgement of the contractor, a number of models have been proposed in the literature to support this process. The present paper proposes the use of statistical classification methods. The response obtained from the classification model is a recommendation to participate or not. A database consisting of historical data was used for the analyses. Two models were proposed: the LOG model—using logit regression and the LDA model—using linear discriminant analysis, which obtain better results. In the construction of the LDA model, the equation of the discriminant function was sought by indicating the statistically significant variables. For this purpose, the backward stepwise method was applied, where initially all input variables were introduced, namely, 15 identified bidding factors, and then in subsequent steps, the least statistically significant variables were removed. Finally, six variables (factors) were identified that significantly discriminate between groups: type of works, contractual conditions, project value, need for work, possible participation of subcontractors, and the degree of difficulty of the works. The model proposed in this paper using a discriminant analysis with six input variables achieved good performance. The results obtained prove that it can be used in practice. It should be emphasized, however, that mathematical models cannot replace the decision-maker’s thought process, but they can increase the effectiveness of the bidding decision.
Agnieszka Leśniak. Statistical Methods in Bidding Decision Support for Construction Companies. Applied Sciences 2021, 11, 5973 .
AMA StyleAgnieszka Leśniak. Statistical Methods in Bidding Decision Support for Construction Companies. Applied Sciences. 2021; 11 (13):5973.
Chicago/Turabian StyleAgnieszka Leśniak. 2021. "Statistical Methods in Bidding Decision Support for Construction Companies." Applied Sciences 11, no. 13: 5973.
Proper quality assessment of ready-mixed concrete, which is currently the principal material for construction, land engineering and architecture, has an impact on the optimisation and verification of correct functioning of individual stages of the production process. According to the European Standard EN 206 “Concrete–Specification, performance, production and conformity”, obligatory conformity control of concrete is carried out by the producer during its production. In order to verify the quality of concrete, investors generally commission independent laboratory units to perform quality assessment of both concrete mix and hardened concrete, which guarantees a high quality of construction works. One of the essential tools for ensuring the quality of test results is the participation of laboratories in the so-called proficiency testing (PT) or inter-laboratory comparisons (ILC). Participation in PT/ILC programmes is, on the one hand, a tool for demonstrating the laboratory’s performance, on the other hand an aid for maintaining the quality of available concrete tests and validating test methods. Positive evaluation is a confirmation of the laboratory’s capability for performing the tests. The paper presents the results of laboratory proficiency tests carried out by means of inter-laboratory comparisons, as shown in the example of quality assessment of ready-mixed concrete for nine participating laboratories. The tests were performed for concrete of the following parameters: strength class C30/37, consistency S3, frost resistance degree F150, and water resistance degree W8. This involved determining consistencies, air content and density of the concrete mix, and compressive strength of hardened concrete. For the evaluation of laboratory performance results, z-score, ζ-score and En-score were applied. The innovation of the proposed study lies in employing both classical and iterative robust statistical methods. In comparison with classical statistical methods, robust methods ensure a smaller impact of outliers and other anomalies on the measurement results. Following the analyses, clear differences were found between the types of detected discrepancy of test results, which occurred due to the nature of individual parameters. For two laboratories, two scores revealed unsatisfactory results for concrete mix consistency. The main reasons can be pouring into the cone-shaped form a concrete mixture that is too dry, or incorrect use of a measuring tool also creating a possibility that the obtained value can be wrongly recorded. Other possible reasons are discussed in the paper. Participation in inter-laboratory comparison programmes is undoubtedly a way to verify and raise the quality of tests performed for concrete mix and hardened concrete, whereas individual analysis of the results allows the laboratory quality system to be improved.
Izabela Skrzypczak; Agnieszka Leśniak; Piotr Ochab; Monika Górka; Wanda Kokoszka; Anna Sikora. Interlaboratory Comparative Tests in Ready-Mixed Concrete Quality Assessment. Materials 2021, 14, 3475 .
AMA StyleIzabela Skrzypczak, Agnieszka Leśniak, Piotr Ochab, Monika Górka, Wanda Kokoszka, Anna Sikora. Interlaboratory Comparative Tests in Ready-Mixed Concrete Quality Assessment. Materials. 2021; 14 (13):3475.
Chicago/Turabian StyleIzabela Skrzypczak; Agnieszka Leśniak; Piotr Ochab; Monika Górka; Wanda Kokoszka; Anna Sikora. 2021. "Interlaboratory Comparative Tests in Ready-Mixed Concrete Quality Assessment." Materials 14, no. 13: 3475.
BIM (building information modeling) is a kind of technology that has great potential to enhance the level of automation in architecture, engineering, and construction (AEC) projects. The created virtual model of the facility allows coordinating all industries during the entire life cycle of the building. The possibility to save the data related to the given facility in one place, namely in the BIM model, enables control and management of the AEC projects at every stage. During the design and implementation phase, BIM models facilitate the optimization of time, costs, and quality, and in the operational phase, they support effective management of the facility. The use of BIM for building energy modeling (BEM) is the next step of evolution in architecture and engineering design practice. The benefits of using the BIM approach are widely discussed in the literature; however, they may be hard to achieve if appropriate attention is not directed to minimizing the barriers to the implementation of this technology. Observing Europe, one can notice that western and northern countries successfully use BIM for their needs, while the countries of the Eastern Bloc, including Poland, introduce it at a slower pace. In the present paper, the authors conducted a cause-and-effect analysis of the identified barriers to the implementation of BIM technology in the construction process. For this purpose, the authors applied the Ishikawa diagram, which is a tool that helps to recognize the actual or potential causes of failure. The analysis conducted showed that one of the weakest links in the successful BIM implementation is people and, in particular, their lack of knowledge and reluctance to change. The authors indicated the need to introduce and strengthen preventive actions, mainly through education: training, courses, and studies focused on BIM technology.
Agnieszka Leśniak; Monika Górka; Izabela Skrzypczak. Barriers to BIM Implementation in Architecture, Construction, and Engineering Projects—The Polish Study. Energies 2021, 14, 2090 .
AMA StyleAgnieszka Leśniak, Monika Górka, Izabela Skrzypczak. Barriers to BIM Implementation in Architecture, Construction, and Engineering Projects—The Polish Study. Energies. 2021; 14 (8):2090.
Chicago/Turabian StyleAgnieszka Leśniak; Monika Górka; Izabela Skrzypczak. 2021. "Barriers to BIM Implementation in Architecture, Construction, and Engineering Projects—The Polish Study." Energies 14, no. 8: 2090.
One of the problems in cities is improving energy efficiency. Energy consumption and the efficient use of district heating networks affect the environment, society, and economy. Modern materials to increase buildings' energy efficiency become necessary. The use of phase change materials (PCM) is a current issue and many researchers' interest. PCM reduces energy consumption in buildings due to their ability to absorb and release energy. PCM use seems to be highly justified as regards energy efficiency policy-making considering the city's investment scale. Therefore, research was undertaken on the possibility of reducing energy consumption in the city by using PCM in municipal heating networks, as those for which planning can be carried out systemically. The research's original element is integrating geographic systems with artificial intelligence and statistical methods to estimation the probability of improving buildings' energy efficiency in urban areas based on an identified set of criteria of an interdisciplinary type. The proposed innovative approach was used to analyze the medium-sized city located in Eastern Europe. The results showed that buildings could be classified according to the probability of energy improvement at the limit of 30%. Suggestions were made for adapting the proposed method to more general cases.
Marta Skiba; Maria Mrówczyńska; Małgorzata Sztubecka; Anna Bazan-Krzywoszańska; Jan K. Kazak; Agnieszka Leśniak; Filip Janowiec. Probability estimation of the city’s energy efficiency improvement as a result of using the phase change materials in heating networks. Energy 2021, 228, 120549 .
AMA StyleMarta Skiba, Maria Mrówczyńska, Małgorzata Sztubecka, Anna Bazan-Krzywoszańska, Jan K. Kazak, Agnieszka Leśniak, Filip Janowiec. Probability estimation of the city’s energy efficiency improvement as a result of using the phase change materials in heating networks. Energy. 2021; 228 ():120549.
Chicago/Turabian StyleMarta Skiba; Maria Mrówczyńska; Małgorzata Sztubecka; Anna Bazan-Krzywoszańska; Jan K. Kazak; Agnieszka Leśniak; Filip Janowiec. 2021. "Probability estimation of the city’s energy efficiency improvement as a result of using the phase change materials in heating networks." Energy 228, no. : 120549.
The paper discusses the problems connected with long-term exploitation of reinforced concrete post-tensioned girders. The scale of problems in the world related to the number of cable post-tensioned concrete girders built in the 1950s and still in operation is very large and possibly has very serious consequences. The paper presents an analysis and evaluation of the results of measurements of the deflection and strength and homogeneity of concrete in cable–concrete roof girders of selected industrial halls located in Poland, exploited for over 50 years. On the basis of the results of displacement monitoring in the years 2009–2020, the maximum increments of deflection of the analyzed girders were determined. Non-destructive, destructive, and indirect evaluation methods were used to determine the compressive strength of concrete. Within the framework of the indirect method recommended in standard PN-EN 13791, a procedure was proposed by the authors to modify the so-called base curve for determining compressive strength. Due to the age of the analyzed structural elements, a correction factor for the age of concrete was taken into account in the strength assessment. The typical value of the characteristic compressive strength is within the range 20.3–28.4 MPa. As a result of the conducted tests, the concrete class assumed in the design was not confirmed, and its classification depended on the applied test method. The analyzed girders, in spite of their long-term exploitation, can be still used for years on the condition that regular periodical inspections of their technical condition are carried out. The authors emphasize the necessity for a permanent and cyclic diagnostic process and monitoring of the geometry of girders, as they are expected to operate much longer than was assumed by their designers.
Lukasz Bednarz; Dariusz Bajno; Zygmunt Matkowski; Izabela Skrzypczak; Agnieszka Leśniak. Elements of Pathway for Quick and Reliable Health Monitoring of Concrete Behavior in Cable Post-Tensioned Concrete Girders. Materials 2021, 14, 1503 .
AMA StyleLukasz Bednarz, Dariusz Bajno, Zygmunt Matkowski, Izabela Skrzypczak, Agnieszka Leśniak. Elements of Pathway for Quick and Reliable Health Monitoring of Concrete Behavior in Cable Post-Tensioned Concrete Girders. Materials. 2021; 14 (6):1503.
Chicago/Turabian StyleLukasz Bednarz; Dariusz Bajno; Zygmunt Matkowski; Izabela Skrzypczak; Agnieszka Leśniak. 2021. "Elements of Pathway for Quick and Reliable Health Monitoring of Concrete Behavior in Cable Post-Tensioned Concrete Girders." Materials 14, no. 6: 1503.
The local spatial development plan is an instrument of spatial policy which aims at shaping spatial order. The local plan includes solutions ensuring protection against emerging pollutants, as well as restoring the environment to its proper condition and setting the conditions for the implementation of projects, enabling optimal effects in the field of environmental protection. Land use and land development should also ensure the preservation of all landscape values as much as possible. When creating and adopting a local spatial development plan, a municipality as a local government unit must take into account both public and private interests. The paper attempts to answer the question whether city planning has an impact on investors' activity on the real estate market. Four selected cities located in different parts of Poland were analysed. The authors proposed determining the investor activity indicator as a measure of this impact.
A Leśniak; E Plebankiewicz; R Kozik; K Amanowicz-Marcinkowska. Impact of the current local spatial development plans on the activity of investor on the Polish residential real estate market. IOP Conference Series: Earth and Environmental Science 2021, 656, 012004 .
AMA StyleA Leśniak, E Plebankiewicz, R Kozik, K Amanowicz-Marcinkowska. Impact of the current local spatial development plans on the activity of investor on the Polish residential real estate market. IOP Conference Series: Earth and Environmental Science. 2021; 656 (1):012004.
Chicago/Turabian StyleA Leśniak; E Plebankiewicz; R Kozik; K Amanowicz-Marcinkowska. 2021. "Impact of the current local spatial development plans on the activity of investor on the Polish residential real estate market." IOP Conference Series: Earth and Environmental Science 656, no. 1: 012004.
Zofia Zięba; Jolanta Dąbrowska; Marian Marschalko; Jorge Pinto; Maria Mrówczyńska; Agnieszka Leśniak; Aleksandar Petrovski; Jan K Kazak. Built Environment Challenges Due to Climate Change. IOP Conference Series: Earth and Environmental Science 2020, 609, 1 .
AMA StyleZofia Zięba, Jolanta Dąbrowska, Marian Marschalko, Jorge Pinto, Maria Mrówczyńska, Agnieszka Leśniak, Aleksandar Petrovski, Jan K Kazak. Built Environment Challenges Due to Climate Change. IOP Conference Series: Earth and Environmental Science. 2020; 609 ():1.
Chicago/Turabian StyleZofia Zięba; Jolanta Dąbrowska; Marian Marschalko; Jorge Pinto; Maria Mrówczyńska; Agnieszka Leśniak; Aleksandar Petrovski; Jan K Kazak. 2020. "Built Environment Challenges Due to Climate Change." IOP Conference Series: Earth and Environmental Science 609, no. : 1.
Control of technical parameters obtained by ready-mixed concrete may be carried out at different stages of the development of concrete properties and by different participants involved in the construction investment process. According to the European Standard EN 206 “Concrete–Specification, performance, production and conformity”, mandatory control of concrete conformity is conducted by the producer during production. As shown by the subject literature, statistical criteria set out in the standard, including the method for concrete quality assessment based on the concept of concrete family, continue to evoke discussions and raise doubts. This justifies seeking alternative methods for concrete quality assessment. This paper presents a novel approach to quality control and classification of concrete based on combining statistical and fuzzy theories as a means of representation of two types of uncertainty: random uncertainty and information uncertainty. In concrete production, a typical situation when fuzzy uncertainty can be taken into consideration is the conformity control of concrete compressive strength, which is conducted to confirm the declared concrete class. The proposed procedure for quality assessment of a concrete batch is based on defining the membership function for the considered concrete classes and establishing the degree of belonging to the considered concrete class. It was found that concrete classification set out by the standard includes too many concrete classes of overlapping probability density distributions, and the proposed solution was to limit the scope of compressive strength to every second class so as to ensure the efficacy of conformity assessment conducted for concrete classes and concrete families. The proposed procedures can lead to two types of decisions: non-fuzzy (crisp) or fuzzy, which point out to possible solutions and their corresponding preferences. The suggested procedure for quality assessment allows to classify a concrete batch in a fuzzy way with the degree of certainty less than or equal to 1. The results obtained confirm the possibility of employing the proposed method for quality assessment in the production process of ready-mixed concrete.
Izabela Skrzypczak; Wanda Kokoszka; Joanna Zięba; Agnieszka Leśniak; Dariusz Bajno; Lukasz Bednarz. A Proposal of a Method for Ready-Mixed Concrete Quality Assessment Based on Statistical-Fuzzy Approach. Materials 2020, 13, 5674 .
AMA StyleIzabela Skrzypczak, Wanda Kokoszka, Joanna Zięba, Agnieszka Leśniak, Dariusz Bajno, Lukasz Bednarz. A Proposal of a Method for Ready-Mixed Concrete Quality Assessment Based on Statistical-Fuzzy Approach. Materials. 2020; 13 (24):5674.
Chicago/Turabian StyleIzabela Skrzypczak; Wanda Kokoszka; Joanna Zięba; Agnieszka Leśniak; Dariusz Bajno; Lukasz Bednarz. 2020. "A Proposal of a Method for Ready-Mixed Concrete Quality Assessment Based on Statistical-Fuzzy Approach." Materials 13, no. 24: 5674.
The beginning of each construction investment is preceded by proper preparation. In the case of public procurement, this usually involves conducting a tender procedure to select a contractor for the works.Railway construction works require this rigor. This article will provide an overview of railway construction investments planned to be implemented in the current EU financial perspective. The key elements of the tender process related to individual stages of the tender will be analyzed.
Agnieszka Leśniak; Filip Janowiec. Analysis of tender procedure phases parameters for railroad construction works. Open Engineering 2020, 10, 846 -853.
AMA StyleAgnieszka Leśniak, Filip Janowiec. Analysis of tender procedure phases parameters for railroad construction works. Open Engineering. 2020; 10 (1):846-853.
Chicago/Turabian StyleAgnieszka Leśniak; Filip Janowiec. 2020. "Analysis of tender procedure phases parameters for railroad construction works." Open Engineering 10, no. 1: 846-853.
External facades of buildings and other structures shape the image of every building, creating the architecture of cities. Traditional concrete forms, as a symbol of durability and stability, have been replaced by lightweight enclosures—for example, in the form of aluminium–glass facades and ventilated facades. In this paper, the authors attempt to verify the strength of influence and relations between the identified factors shaping the costs of facade system implementation using structural analysis. On the basis of the collected quantitative and qualitative data obtained as a result of research on design documentation and cost estimates of implemented public buildings, as well as on the basis of interviews conducted among experts, factors which have a real impact on the costs of facade systems in the form of aluminium and glass facades and ventilated facades were identified. The indicated factors were analysed and classified using the method of structural analysis, namely the MICMAC method (refers to the French acronym for Cross-Impact Matrix Multiplication Applied to Classification). Particular influences and relations between factors were examined. Finally, six groups of factors influencing the costs of facade systems were identified, including regulatory factors that do not have a very strong impact on the level of costs, but which show a strong correlation with other factors; determinants that have a very strong impact on the costs; and a group of external factors that show the smallest influence on the estimation of façade cost.
Agnieszka Leśniak; Monika Górka. Structural Analysis of Factors Influencing the Costs of Facade System Implementation. Applied Sciences 2020, 10, 6021 .
AMA StyleAgnieszka Leśniak, Monika Górka. Structural Analysis of Factors Influencing the Costs of Facade System Implementation. Applied Sciences. 2020; 10 (17):6021.
Chicago/Turabian StyleAgnieszka Leśniak; Monika Górka. 2020. "Structural Analysis of Factors Influencing the Costs of Facade System Implementation." Applied Sciences 10, no. 17: 6021.
The image of the whole building is primarily its shape, external casing and materials used. The investor has to make a decision already at the moment of preparing the design concept, in which technology and materials the office building or service and commercial object is to be made. Heavy concrete construction has disappeared over the years. Investors decide to use lightweight materials, such as aluminium and glass, to give buildings a light form and to avoid disturbing the architecture of the surrounding urban planning. The multitude of aluminium and glass facade systems offered by the manufacturers makes the investor face a difficult choice of such a system that will meet his or her expectations. The aim of the paper is to describe and evaluate the aluminium and glass facade systems offered by the manufacturers. The analysis was performed for three variants: mullion and transom system, semi-structural system and structural system. A model supporting the decision to choose an appropriate variant based on the identified criteria and multi-criteria Analytic Hierarchy Process method (AHP) was proposed.
Agnieszka Leśniak; Damian Wieczorek; Monika Górka. Selection of the Variant of the Aluminium-Glass Facade Implementation Using the AHP Method. Advances in Intelligent Systems and Computing 2020, 536 -543.
AMA StyleAgnieszka Leśniak, Damian Wieczorek, Monika Górka. Selection of the Variant of the Aluminium-Glass Facade Implementation Using the AHP Method. Advances in Intelligent Systems and Computing. 2020; ():536-543.
Chicago/Turabian StyleAgnieszka Leśniak; Damian Wieczorek; Monika Górka. 2020. "Selection of the Variant of the Aluminium-Glass Facade Implementation Using the AHP Method." Advances in Intelligent Systems and Computing , no. : 536-543.
One of the most important documents occurring in the investment process is the administrative decision: building permit. Obtaining it is often a time-consuming process in practice, associated with the need to attach to the application other required decisions and permits necessary for a positive consideration of the case. The procedure itself is not always a long-term process, as long as the investor makes sure to prepare a reliable application free of errors and irregularities together with the construction project and the required attachments. The purpose of the article is to analyze errors appearing in investors’ applications and attached project documentation required in the administrative procedure for obtaining a building permit in the light of the applicable provisions of Polish law.
Agnieszka Leśniak; Monika Górka; Anna Kargol. Analysis of Errors in Investors’ in the Procedure of Obtaining a Building Permit. Civil and Environmental Engineering Reports 2019, 29, 185 -197.
AMA StyleAgnieszka Leśniak, Monika Górka, Anna Kargol. Analysis of Errors in Investors’ in the Procedure of Obtaining a Building Permit. Civil and Environmental Engineering Reports. 2019; 29 (4):185-197.
Chicago/Turabian StyleAgnieszka Leśniak; Monika Górka; Anna Kargol. 2019. "Analysis of Errors in Investors’ in the Procedure of Obtaining a Building Permit." Civil and Environmental Engineering Reports 29, no. 4: 185-197.
The implementation of railway infrastructure construction projects including sustainable development goals is a complex process characterized by a significant extension of individual investment stages. The need for additional works has a big impact on construction railway projects, representing a risk which is the result of many different factors. During the execution of works, both the design assumptions and the conditions of the project’s implementation can be changed. An attempt to eliminate potential risks is a key element of construction projects. The article proposes a proprietary management method for the risk of additional works in railway projects. A methodology for creating risk management strategies using a standard algorithm that includes risk identification, risk analysis, and risk assessment is presented. The original elements of the work include risk identification followed by analysis using Bayesian networks. Using the example of a scenario of events, it is shown that a well-programmed network can be used to implement risk mitigation methods. Using the network, it is possible to compare different ways to reduce risk, check the effect of reducing the risk factors, and determine a satisfactory level of effects, e.g., increased financial resources as a result of additional works.
Agnieszka Leśniak; Filip Janowiec. Risk Assessment of Additional Works in Railway Construction Investments Using the Bayes Network. Sustainability 2019, 11, 5388 .
AMA StyleAgnieszka Leśniak, Filip Janowiec. Risk Assessment of Additional Works in Railway Construction Investments Using the Bayes Network. Sustainability. 2019; 11 (19):5388.
Chicago/Turabian StyleAgnieszka Leśniak; Filip Janowiec. 2019. "Risk Assessment of Additional Works in Railway Construction Investments Using the Bayes Network." Sustainability 11, no. 19: 5388.
Agnieszka Leśniak; Filip Janowiec. Roboty dodatkowe w kolejowych przedsięwzięciach budowlanych. ACTA SCIENTIARUM POLONORUM - Architectura Budownictwo 2019, 18, 33 -42.
AMA StyleAgnieszka Leśniak, Filip Janowiec. Roboty dodatkowe w kolejowych przedsięwzięciach budowlanych. ACTA SCIENTIARUM POLONORUM - Architectura Budownictwo. 2019; 18 (2):33-42.
Chicago/Turabian StyleAgnieszka Leśniak; Filip Janowiec. 2019. "Roboty dodatkowe w kolejowych przedsięwzięciach budowlanych." ACTA SCIENTIARUM POLONORUM - Architectura Budownictwo 18, no. 2: 33-42.
The railway construction investments are characterized by a significant extension of individual phases and an increased number of entities participating in the construction investment process. Despite the use of many modern methods and techniques unforeseen phenomena and events which may occur during the execution of the investment cannot be excluded. All unexpected situations usually initiate consequences in the form of additional workload and costs not included by the contractor and longer duration of works. This fact is commonly referred to as the occurrence of the so-called additional works. The paper presents the results of research concerning additional works occurring during the realization of railway construction projects performed in southern Poland. The analysis was based on data which concerned projects completed in the period from 1 January 2012 to 31 December 2018.
Agnieszka Leśniak; Filip Janowiec. Analysis of additional works in completed railway construction projects. Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 2019, 28, 366 -376.
AMA StyleAgnieszka Leśniak, Filip Janowiec. Analysis of additional works in completed railway construction projects. Przegląd Naukowy Inżynieria i Kształtowanie Środowiska. 2019; 28 (3):366-376.
Chicago/Turabian StyleAgnieszka Leśniak; Filip Janowiec. 2019. "Analysis of additional works in completed railway construction projects." Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 28, no. 3: 366-376.
New materials for thermal insulation and thermo-modernization of buildings are still developing. The potential investor is faced with the problem of choosing the most advantageous option. Each material can be characterized by a large catalogue of criteria. The selection of the most advantageous solution may be supported by the multi-criteria analysis method. The list and the range of the criteria depends on the decision maker. The paper presents a method that will allow a potential investor to easily select the most advantageous solution.
Renata Kozik; Agnieszka Leśniak; Marcin Majka. Application of multi-criteria analysis method for thermal insulation solutions selection. CENTRAL EUROPEAN SYMPOSIUM ON THERMOPHYSICS 2019 (CEST) 2019, 2116, 180010 .
AMA StyleRenata Kozik, Agnieszka Leśniak, Marcin Majka. Application of multi-criteria analysis method for thermal insulation solutions selection. CENTRAL EUROPEAN SYMPOSIUM ON THERMOPHYSICS 2019 (CEST). 2019; 2116 (1):180010.
Chicago/Turabian StyleRenata Kozik; Agnieszka Leśniak; Marcin Majka. 2019. "Application of multi-criteria analysis method for thermal insulation solutions selection." CENTRAL EUROPEAN SYMPOSIUM ON THERMOPHYSICS 2019 (CEST) 2116, no. 1: 180010.
A reliable estimation of the tender prices for lightweight curtain walls is a complex and time-consuming process for the contractor, as it depends on many factors related to both the technical parameters of the designed façade and the investor’s requirements for the solutions selected. The aim of the paper is to identify the factors affecting the costs of manufacturing lightweight curtain walls. Data regarding the complexity of curtain wall construction costs was obtained on the basis of the analysis of project documentation, cost estimates and as-built accounts for selected 50 public buildings. The authors identified the factors affecting the costs of aluminum-glass facades and ventilated facades. Their identification is the first element necessary to develop a new method of predicting the costs of implementation of such types of facade which are included in the authors’ research plans.
Agnieszka Leśniak; Monika Górka; Damian Wieczorek. Identification of factors shaping tender prices for lightweight. Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 2019, 28, 171 -182.
AMA StyleAgnieszka Leśniak, Monika Górka, Damian Wieczorek. Identification of factors shaping tender prices for lightweight. Przegląd Naukowy Inżynieria i Kształtowanie Środowiska. 2019; 28 (2):171-182.
Chicago/Turabian StyleAgnieszka Leśniak; Monika Górka; Damian Wieczorek. 2019. "Identification of factors shaping tender prices for lightweight." Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 28, no. 2: 171-182.
Construction projects, even exemplarily planned and organized, bear a risk of unforeseen events and problems which can result in completion of the works after the deadline, that is delays. The construction of bridges is an inseparable part of road and rail projects and construction and expansion of the transport network. The paper aims at finding a relationship between the independent variables characterizing bridge projects and the delays during their implementation. Two alternative models were proposed to solve the problem: logit and probit. The data set comprising road and rail bridges built in Poland in the last 12 years (2005 – 2017) was used to build the models. The evaluation, quality and accuracy parameters of proposed models were determined in the final part of the paper.
A. Leśniak; M. Juszczyk; G. Piskorz. Modelling Delays in Bridge Construction Projects Based on the Logit and Probit Regression. Archives of Civil Engineering 2019, 65, 107 -120.
AMA StyleA. Leśniak, M. Juszczyk, G. Piskorz. Modelling Delays in Bridge Construction Projects Based on the Logit and Probit Regression. Archives of Civil Engineering. 2019; 65 (2):107-120.
Chicago/Turabian StyleA. Leśniak; M. Juszczyk; G. Piskorz. 2019. "Modelling Delays in Bridge Construction Projects Based on the Logit and Probit Regression." Archives of Civil Engineering 65, no. 2: 107-120.
The architecture of the 21st century requires the designer to create a modern, light and aesthetic shape. Such effect can be obtained by creating an external facade in the form of a light curtain wall as an aluminum and glass facade. Aluminum and glass facades have to meet not only technical requirements such as safety, thermal insulation, sound insulation, but also should be economically viable for the potential recipient. The paper presents three variants of aluminum and glass facades: column—transom, structural and semi—structural. For the application of each, advantages and disadvantages are presented. Additionally, the article presents calculation and cost structure of the aluminum and glass facade. Every option has been assessed for economic viability and the possibility of using it in modern constructions.
Agnieszka Leśniak; M. Górka. Analysis of the cost structure of aluminum and glass facades. Advances and Trends in Engineering Sciences and Technologies III 2019, 445 -450.
AMA StyleAgnieszka Leśniak, M. Górka. Analysis of the cost structure of aluminum and glass facades. Advances and Trends in Engineering Sciences and Technologies III. 2019; ():445-450.
Chicago/Turabian StyleAgnieszka Leśniak; M. Górka. 2019. "Analysis of the cost structure of aluminum and glass facades." Advances and Trends in Engineering Sciences and Technologies III , no. : 445-450.
Construction site overhead costs are key components of cost estimation in construction projects. The estimates are expected to be accurate, but there is a growing demand to shorten the time necessary to deliver cost estimates. The balancing (symmetry) between time of calculation and satisfaction of reliable estimation was the reason for developing a new model for cost estimation in construction. This paper reports some results from the authors’ broad research on the modelling processes in engineering related to estimation of construction costs using artificial intelligence tools. The aim of this work was to develop a model capable of predicting a construction site cost index that would benefit from combining several artificial neural networks into an ensemble. Combining selected neural networks and forming the ensemble-based models compromised their strengths and weaknesses. With the use of data including training patterns collected on the basis of studies of completed construction projects, the authors investigated various types of neural networks in order to select the members of the ensemble. Finally, three models that were assessed in terms of performance and prediction quality were proposed. The results revealed that the developed models based on ensemble averaging and stacked generalisation met the expectations of knowledge generalisation and accuracy of prediction of site overhead cost index. The proposed models offer predictions of cost in an accepted error range and prove to deliver better predictions than those based on single neural networks. The developed tools can be used in the decision-making process regarding construction cost estimation.
Michał Juszczyk; Agnieszka Leśniak. Modelling Construction Site Cost Index Based on Neural Network Ensembles. Symmetry 2019, 11, 411 .
AMA StyleMichał Juszczyk, Agnieszka Leśniak. Modelling Construction Site Cost Index Based on Neural Network Ensembles. Symmetry. 2019; 11 (3):411.
Chicago/Turabian StyleMichał Juszczyk; Agnieszka Leśniak. 2019. "Modelling Construction Site Cost Index Based on Neural Network Ensembles." Symmetry 11, no. 3: 411.